Heated condensate drainage tube

ABSTRACT

A passive heater for heating a drainage tube, the passive heater including: an elongated flexible thermal conductor including a first end and a second end, wherein the first end is configured to be disposed in contacting relationship with a heat source and at least a portion of the elongated flexible thermal conductor is configured to be disposed in contacting relationship with a portion of the drainage tube; and an eyelet disposed on the first end, the eyelet configured to facilitate the securement of the elongated flexible thermal conductor to the heat source, wherein the first end is configured to receive heat and transmit it along the elongated flexible thermal conductor to increase temperature of the portion of the drainage tube to prevent freezing of a fluid through the drainage tube.

PRIORITY CLAIM AND RELATED APPLICATIONS

This divisional application claims the benefit of priority fromnon-provisional application Ser. No. 16/458,629 filed on Jul. 1, 2019.Said application is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION 1. The Field of the Invention

The present invention relates to a heated drainage tube. Morespecifically, the present invention is directed to heated condensatedrainage tube.

2. Background Art

During operation, a hydrocarbon fuel-consuming high efficiency heatingsystem produces condensates that must be drained through drainage tubes.In some occasions, its condensate drainage tube may be exposed totemperatures at or below the freezing point causing the contents of thedrainage tube, i.e., condensates, to zo freeze, creating a blockage tothe condensate drainage tube. There exists a need for a freeze-proofcondensate drainage tube.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a passiveheater for heating a drainage tube, the passive heater including:

-   -   (a) an elongated flexible thermal conductor including a first        end and a second end, wherein the first end is configured to be        disposed in contacting relationship with a heat source and at        least a portion of the elongated flexible thermal conductor is        configured to be disposed in contacting relationship with a        portion of the drainage tube; and    -   (b) an eyelet disposed on the first end, the eyelet configured        to facilitate the securement of the elongated flexible thermal        conductor to the heat source,        wherein the first end is configured to receive heat and transmit        it along the elongated flexible thermal conductor to increase        temperature of the portion of the drainage tube to prevent        freezing of a fluid through the drainage tube.

In one embodiment, the first end of the elongated flexible thermalconductor includes a plurality of branches configured for receiving heatfrom the heat source that is a plurality of heat sources. In oneembodiment, at least one of said plurality of branches is at leastpartially insulated.

In accordance with the present invention, there is further provided apassive heater for heating a drainage tube, the passive heaterincluding:

-   -   (a) an elongated flexible thermal conductor including a first        end and a second end, wherein the first end is configured to be        disposed in contacting relationship with a collective heat        source and at least a portion of the elongated flexible thermal        conductor is configured to be disposed in contacting        relationship with a portion of the drainage tube; and    -   (b) a collar disposed on the first end of the elongated flexible        thermal conductor, the collar is thermally connected to the        elongated flexible thermal conductor, the collar includes at        least one receptacle configured to receive the collective heat        source,        wherein heat from the collective heat source is transmittable to        the portion of the drainage tube to increase temperature of the        portion of the drainage tube.

In one embodiment, the passive heater further includes a branch having afirst end and a second end, wherein the first end of the branch isconfigured to receive a contributory heat source, heat received from thecontributory heat source is transmittable to the second end of thebranch, the second end of the branch is configured to be thermallyconnected to the at least one receptacle such that heat received fromthe contributory heat source is transmittable as at least a portion ofthe collective heat source. In one embodiment, the branch is at leastpartially insulated. In one embodiment, the contacting relationshipincludes contact of the elongated flexible thermal conductor with anouter wall surface of the portion of the drainage tube. In oneembodiment, the contacting relationship includes contact of theelongated flexible thermal conductor with an inner wall surface of theportion of the drainage tube. In one embodiment, the contactingrelationship includes contact of the elongated flexible thermalconductor within a wall of the portion of the drainage tube.

In accordance with the present invention, there is further provided apassive heater for heating a drainage tube, the passive heater includinga fluid jacket including an inlet port and an outlet port, wherein theinlet port is configured to receive a fluid and at least a portion ofthe fluid jacket is configured to be disposed in a contactingrelationship with the drainage tube such that the drainage tube can beheated by the fluid to prevent freezing of a drainage through thedrainage tube and said outlet port is configured to return the fluid.

In one embodiment, the fluid is a liquid. In another embodiment, thefluid is a gas.

An object of the present invention is to provide a means for preventingand/or inhibiting freezing of condensates from the combustion of ahydrocarbon fuel.

Another object of the present invention is to provide a passive meansfor preventing and/or inhibiting freezing of condensates from thecombustion of a hydrocarbon fuel.

Another object of the present invention is to provide a means forpreventing and/or inhibiting freezing of condensates from the combustionof a hydrocarbon fuel where the means is available on demand.

Another object of the present invention is to provide a means forpreventing and/or inhibiting freezing of condensates from the combustionof a hydrocarbon fuel where the means is not significantly impacting theresources allocated for domestic water and space heating purposes.

Whereas there may be many embodiments of the present invention, eachembodiment may meet one or more of the foregoing recited objects in anycombination. It is not intended that each embodiment will necessarilymeet each objective. Thus, having broadly outlined the more importantfeatures of the present invention in order that the detailed descriptionthereof may be better understood, and that the present contribution tothe art may be better appreciated, there are, of course, additionalfeatures of the present invention that will be described herein and willform a part of the subject matter of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above-recited and other advantagesand objects of the invention are obtained, a more particular descriptionof the invention briefly described above will be rendered by referenceto specific embodiments thereof which are illustrated in the appendeddrawings. Understanding that these drawings depict only typicalembodiments of the invention and are not therefore to be considered tobe limiting of its scope, the invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 is a diagram depicting a condensate drainage tube adapted todrain condensates generated from a water heater.

FIG. 2 is a diagram depicting an augmented condensate drainage tubeadapted to drain condensates generated from a water heater.

FIG. 3 is a diagram depicting a purpose-built thermal conductor usefulfor augmenting the temperature of a condensate drainage tube adapted todrain condensates generated from a water heater.

FIGS. 4-6 are diagrams depicting various possible configurations of athermal conductor useful for augmenting the temperature of a condensatedrainage tube adapted to drain condensates generated from a waterheater.

FIG. 7 is a diagram depicting one scenario where branched thermalconductors may be used to receive heat from heat sources.

FIG. 8 is a close-up view of one scenario where a thermal conductor maybe used to heat a condensate drainage tube.

FIG. 9 is a diagram depicting size relationships between branch and mainthermal conductors.

FIG. 10 is a diagram depicting one embodiment of a condensate drainagetube configured for receiving heat through removable branches.

FIG. 11 is a diagram depicting another means for heating a condensatedrainage tube.

PARTS LIST

-   2—drainage tube-   4—thermal conductor-   6—tube wall-   8—eyelet or washer or ring-   10—heating system-   12—thermal source-   14—thermal sink-   16—frozen condensate-   18—exhaust of drainage tube-   20—drain grate-   22—drain-   24—door-   26—louver-   28—cold air flow-   30—branch thermal conductor-   32—section with higher density thermal conductor-   34—section with lower density thermal conductor-   36—fastener-   38—receptacle-   40—fastener-   42—eyelet-   44—insulator-   46—connector-   48—cross-sectional area of branch thermal conductor-   50—cross-sectional area of thermal conductor-   52—inlet-   53—outlet-   54—stub-   56—heated fluid conductor-   58—jacket-   60—fitting-   62—tubing-   64—collar-   66—partition-   68—direction

PARTICULAR ADVANTAGES OF THE INVENTION

The present heated condensate drainage tube or thermal conductorconfigured for heating a condensate drainage tube enables condensates toremain in the liquid form such that they can continue to be drained evenwhen the local ambient temperature of the condensate drainage tube hasdropped to or below the freezing point.

The present heated condensate drainage tube or thermal conductorconfigured for heating a condensate drainage tube is configured to tapinto one or more existing heat sources already made available for fluidheating. No dedicated or new heat sources are required to preventcondensates from freezing, thereby simplifying the manner in whichcondensates are kept in the liquid form such that they can continue tobe drained even when the local ambient temperature of the drainage tubehas dropped to or below the freezing point.

In one embodiment, the present thermal conductor is built into or builtintegrally with a condensate drainage tube, thereby simplifying themanner which the condensate drainage tube is heated. In one embodiment,heat is fed into the condensate drainage tube at its first end via acollar configured for receiving one or more branches. This allowsbranches of appropriate length to be selected for use, eliminating theuse of branches that are unnecessarily long and keeping the thermalconductor and condensate drainage tube neat and easily serviceable andheat transfer through to the condensate drainage tube efficient.

The present heated condensate drainage tube or thermal conductorconfigured for heating a condensate drainage tube is operational only ondemand. In other words, the present heated condensate drainage tube orthermal conductor configured for heating a condensate drainage tube isoperational only when it is necessary to do so. The concerns ofcondensate freeze only exist when condensates are generated, i.e., onlywhen the combustion of a hydrocarbon fuel has occurred. Therefore,without a demand, no condensates would have been generated that wouldneed to be drained.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The term “about” is used herein to mean approximately, roughly, around,or in the region of. When the term “about” is used in conjunction with anumerical range, it modifies that range by extending the boundariesabove and below the numerical values set forth. In general, the term“about” is used herein to modify a numerical value above and below thestated value by a variance of 20 percent up or down (higher or lower).

FIG. 1 is a diagram depicting a condensate drainage tube 2 adapted todrain condensates generated from a water heater 10. The water heaterrelies on the combustion of a hydrocarbon fuel to generate heat.Condensate generation is one of the hallmarks of a high efficiency(e.g., greater than 90% efficiency) condensing combustion system. A highefficiency condensing combustion system achieves high efficiency bycondensing water vapor in the flue gases and recovering its latent heatof vaporization. The result is condensed vapor that is typicallycollected and put through a neutralizer and drained. Condensate is anacidic solution containing various concentrations of nitric, nitrous,sulfuric, sulfurous acids and hydrochloric acids and can be harmful fordrainage pipes, septic tanks, treatment plants and other waste handlingsystems. In conventional neutralizer systems, calcium carbonate may beused as a neutralizing agent to raise the pH of collected condensatebefore it is drained as an effluent. No neutralizer systems are shownbut rather a condensate drainage tube 2 is shown to be directed to adrain 22. A first end of the condensate drainage tube 2 is connected toeither a pre-neutralized drain portion, e.g., the drainage line or part56 of U.S. patent application Ser. No. 15/859,169 (if no condensateneutralization is desired) or a post-neutralized drain portion, e.g.,the outlet of the condensate neutralizer or part 54 of the '169application (if condensate neutralization is desired). A second end ofthe condensate drainage tube 2 or the exhaust 18 of the drainage tube ispreferably and typically secured to a drain grate 20 to ensure that thecondensate or neutralized condensate is directed by gravity down andinto the drain 22. Under certain ambient conditions, the second end ofthe drainage tube tends to be clogged due to the cold air flow 28 whichenters the mechanical room in which the water heater and the drainagetube 2 are disposed and sinks to the lowest point of the mechanicalroom, i.e., the mechanical room floor which at least a portion of thecondensate drainage tube 2 runs. The movement of cold air is enhancedwhen a door 24 to the mechanical room is equipped with louvers 26. Asthe condensate arrives by gravity at or near the exhaust 18, it wouldhave lost sufficient heat to the surroundings of the drainage tube 2.Left unattended for a prolonged period at sufficiently low temperatureat or near the exhaust 18, frozen condensate 16 can form at or near theexhaust 18, backing up further condensate flow to the inlet of thedrainage tube 2 and affecting the efficient operation or the operationof a condensate neutralizer or water heater to which the drainage tube 2is connected. A number of corrective measures may be taken to addressthe issue where condensates freeze that prevent efficient flow of thecondensates. The mechanical room may be made more airtight to preventcold flow to enter it. The ambient temperature of the mechanical roommay be increased to ensure that no parts of the mechanical room willexperience temperature that is sufficiently low where freezing of thecondensates can occur. However, such measures will require sufficientenergy to be expended for the sole purpose of preventing the freezing ofcondensates. The ensuing disclosure reveals an apparatus useful forpreventing freezing of condensates without requiring an additionalheating source to the apparatuses that create the condensates in thefirst place. Further, in one embodiment, the heat energy used forpreventing freezing of condensates is sourced from one or morecomponents of the water heater which would otherwise be wasted. Forinstance, the bottom casting of a coil tube water heater configured tochannel flue gas out to the exhaust has already be disposed at atemperature higher than the exhaust of the drainage tube during theoperation of the water heater. In another embodiment, heat energy, mayin addition, be sourced from an outlet of the water heater. Therefore,the present heated condensate drainage tube or thermal conductorconfigured for heating a condensate drainage tube can be said to be a“passive” device or apparatus.

FIG. 2 is a diagram depicting an augmented condensate drainage tube 2adapted to drain condensates generated from a water heater. It shall benoted that, in this embodiment, a thermal conductor 4 is now wrappedaround a conventional drainage tube 2 to transmit heat from a thermalsource 12 to a thermal sink 14 which is disposed at or near the exhaustof 18 of the drainage tube 2. The thermal source 12 is preferably a partthat is heated with heat energy that would be wasted if not tapped into,e.g., from the flue gas of a coil tube heat exchanger directly or theflue gas exhaust of a coil tube heat exchanger, an example of which canbe found in part 36 of U.S. patent application Ser. No. 16/213,930. Inanother example, the thermal source 12 may also be the heated fluid or aproduct of the water heater. Although less desirable as the removal ofheat energy from the heated fluid for the purpose of preventing freezingof the condensates will reduce the water temperature at a point of use,the effects of such a removal of heat energy is negligible in terms ofthe lower temperature at the point of use or the additional energyrequired to replenish the energy drawn for this purpose.

FIG. 3 is a diagram depicting a purpose-built thermal conductor usefulfor augmenting the temperature of a condensate drainage tube 2 adaptedto drain condensates generated from a water heater. Here, it can beshown that, in order to receive heat energy from multiple thermalsources, the first end of the thermal conductor may be branched into twobranches 30 or more. In order to facilitate the securement of thethermal conductor 4 to one or more heat sources, an eyelet 8 is disposedon the first end, e.g., by crimping the eyelet 8 onto a branch 30. Ascrew can be used to secure and tighten the eyelet 18 to a thermalsource as long as the surface area of the eyelet 18 that comes incontact with the thermal source is sufficiently large, heat conductionfrom the thermal source to the thermal sink 14 occurs withoutimpediment. The branches 30 and any one of the thermal conductorsdisclosed herein may be constructed from strands of thermal conductors,e.g., copper, etc., that continue on to form a larger-diameter thermalconductor 4. Parts of the thermal conductors 4, 30 not required totransmit heat by conduction to the drainage tube 2, may be insulated toprevent heat loss along their length from the first end to the secondend. It shall be noted that the branches 30 are insulated withinsulators 44. Branches need not be of the same length. For instance,the branches can be configured for different lengths depending on thereaches required of each branch. All branches are preferably used andshould not be left unconnected to a heat source as an unconnected branchcan become an unused heat sink and the intended heat sink, i.e., thesecond end of the thermal conductor 4 will receive reduced transmissionof heat. In case a surplus branch exists, this branch shall be also bethermally tied to a heat source, e.g., the same heat source anotherbranch 30 is thermally connected to. A drainage tube 2 is encased in thethermal conductor 4 that is braided such that the drainage tube 2 andits contents can be heated by the heat transmitted from the branchthermal conductors 30 to the exhaust 18 of the drainage tube 2. It shallbe noted that the thermal conductor 4 is also insulated with insulators44 to reduce heat loss from the thermal conductor 4 to its surroundings.

FIGS. 4-6 are diagrams depicting various possible configurations of athermal conductor 4 useful for augmenting the temperature of acondensate drainage tube 2 adapted to drain condensates generated from awater heater. Here, the thermal conductor 4 is configured in the form ofa “cage” although it may also be braided as shown in FIG. 3. Note thatthe density of the cage material can be varied along the length of thethermal conductor 4. This is useful if more heating is desired at acertain location of the thermal conductor 4, e.g., at the exhaust 18 ofa drainage tube 2. It shall be noted that section 32 of the thermalconductor is disposed at a higher density than section 34. Further, themanner in which the cage is disposed with respect to the wall 6 of thedrainage tube 2 can also affect the effectiveness of the thermalconductor 4 for preventing freezing of the condensates. FIG. 4 shows acage 4 that is disposed on the exterior surface of the drainage tube 2with the cage 4 coming in contact with the exterior surface of thedrainage tube 2. An insulation 44 may be provided to minimize heat lossfrom the cage to the surroundings of the cage. FIG. 5 shows a cage 4that is disposed within the wall 6 of the drainage tube duringfabrication to form an integral tube wall and cage. The wall 6 can bemade from a uniform material, e.g., polyurethane or another polymer or anon-reacting metal resistant to neutralized or pre-neutralizedcondensates. The wall 6 can also be made from multi-materials, e.g.,metal for the layer enclosed by the cage 4 for excellent heat conductionand polymer for the layer enclosing the cage 4 for excellent insulationto prevent heat loss to the ambient environment of the drainage tube 2.FIG. 6 shows a cage 4 that is disposed within the lumen of the wall 6.Here, some parts of the cage 4 come in direct contact with thecondensates.

FIG. 7 is a diagram depicting one scenario where branched thermalconductors 30 may be used to receive heat from heat sources. Here, thereare two branches 30, each connected to a stub 54. Although each branch30 is shown thermally connected to a stub 54, the wall to which a branch30 is connected can be any wall that is heated in the process of heatinga fluid or medium in the heating system. A fastener 36 is shown beingused to secure a branch 30 to a stub 54 by means of an eyelet 10. Itshall be noted that the eyelets 10 come in direct contact with the wallthat is heated and the fastener 36 with the medium. The medium entersthrough inlet 52 and exits through outlet 53 and the cavity of the stubs54 is exposed to this medium, e.g., at about 140 degrees F. FIG. 8 is aclose-up view of one scenario where a thermal conductor 4 may be used toheat a condensate drainage tube. Here, both the fastener 36 and theeyelet 8 come in direct contact with a solid part but the fastener 36 isnot exposed to the medium. In the embodiment shown, the thermalconductor 4 is wrapped around a conventional drainage tube to providesome heating to the conventional drainage tube.

FIG. 9 is a diagram depicting size relationships between branch and mainthermal conductors 30, 4. Here, the effective cross-sectional area ofeach branch 30 is represented using part 48 and the effectivecross-sectional area of the thermal conductor 4 is represented usingpart 50. The ratio of the total effective branch area 48 to theeffective cross-sectional area 4 of the thermal conductor 4 shall beclose to about 1.0.

FIG. 10 is a diagram depicting one embodiment of a condensate drainagetube 2 configured for receiving heat through removable branches 30. Acollar 64 is disposed on the first end of the drainage tube 2. Aconnector 46, e.g., a male connector, is provided to allow connection ofthe drainage tube 2 to a water heater. A plurality of receptacles 38 areprovided such that one or more branches 30 may be connected to thecollar 64. Branches 30 may be configured at suitable lengths so thatthey may reach appropriate heat sources. Each branch 30 is a thermalconductor having two ends one of which ends is terminated with an eyelet8 and the other one of which is terminated with eyelet 42. To secure abranch 30 to the collar 64, a fastener 40 is used to thread eyelet 42and screwed into a matching receptacle 38. During operation of a waterheater, if the eyelet 8 is determined to be disposed at a temperaturesignificantly higher than the temperature of the connector 46, e.g., byabout 10 degrees F., no isolator that thermally isolates the collar 64and the connector 46 will be needed. However, if the eyelet 8 isdetermined to be disposed at a temperature largely the same as thetemperature of the connector 46, e.g., less than 10 degrees F., anisolator 44 that thermally separates the collar 64 and the connector 46will be necessary. This way, heat received via the eyelet 8 can readilybe conducted through the collar 64 to the second or distal end of thedrainage tube 2.

FIG. 11 is a diagram depicting another means for heating a condensatedrainage tube 2. Here, heat is transferred via a flow establishedthrough the stubs 54 with the flow exiting a stub 54 of a fluidconductor 56 through a jacket 58 via flexible tubings 62 connected tothe stubs 54 and the jacket 58. The jacket 58 is preferably wrappedaround the second end of the drainage tube 2 in the direction indicated,i.e., direction 68, to elevate the temperature of the second end of thedrainage tube 2 and the condensate flowing through the drainage tube 2above the freezing temperature. It shall be noted that, again, thismeans of heating the condensate requires no additional heating elementsother than the devices already used for water heating. The flow can be aheated liquid, e.g., water, flow from a heating system. In anotherembodiment, the flow can be a flue flow, a result of a hydrocarbon fuelcombustion. Partitions 66 disposed within the jacket 58 are provided toforce the flow within the jacket 58 through the entire jacket 58 toensure that condensates are heated properly in the portion of thedrainage tube 2 that is encased in the jacket 58. The jacket 58 and anyone of the thermal conductors 4 disclosed herein may additionally and/oralternatively be used to heat any parts of the heating system/s whichsupply heat to the thermal conductors 4.

The detailed description refers to the accompanying drawings that show,by way of illustration, specific aspects and embodiments in which thepresent disclosed embodiments may be practiced. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice aspects of the present invention. Other embodiments may beutilized, and changes may be made without departing from the scope ofthe disclosed embodiments. The various embodiments can be combined withone or more other embodiments to form new embodiments. The detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the present invention is defined only by the appended claims,with the full scope of equivalents to which they may be entitled. Itwill be appreciated by those of ordinary skill in the art that anyarrangement that is calculated to achieve the same purpose may besubstituted for the specific embodiments shown. This application isintended to cover any adaptations or variations of embodiments of thepresent invention. It is to be understood that the above description isintended to be illustrative, and not restrictive, and that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Combinations of the above embodimentsand other embodiments will be apparent to those of skill in the art uponstudying the above description. The scope of the present disclosedembodiments includes any other applications in which embodiments of theabove structures and fabrication methods are used. The scope of theembodiments should be determined with reference to the appended claims,along with the full scope of equivalents to which such claims areentitled.

What is claimed herein is:
 1. A passive heater for heating a drainagetube, said passive heater comprising a fluid jacket comprising an inletport and an outlet port, wherein said inlet port is configured toreceive a fluid and at least a portion of said fluid jacket isconfigured to be disposed in a contacting relationship with the drainagetube such that the drainage tube can be heated by the fluid to preventfreezing of a drainage through the drainage tube and said outlet port isconfigured to return the fluid.
 2. The passive heater of claim 1,wherein the fluid is a liquid.
 3. The passive heater of claim 1, whereinthe fluid is a gas.